[panick21_]

I don't buy the 'huge blows as the true cross was stolen' story. Christianity did fine for 100s of years in the region. Conversion happened very slowly over a long period of time.

Its not even clear how 'Islamic' the early armies were, they might have considerable Christian and Jewish portions. How differentiated early Islam was from certain version if Christianity is up for debated.

I also think just going with the 'right place, right time' narrative misses good coalition billing, good generalship and other things they did very well. Both Rome and Persia had thought a great number of wars in its history, and faced many 'barbarian' invasion, sometimes from forces that on paper were more impressive, that invaded during ongoing peer conflicts and despite that had been successful.